This invention relates generally as indicated to a direct drive valve and force motor assembly including an interchangeable motor stator assembly. In addition, such invention relates to a system or method for properly aligning the motor stator assembly to the rotor assembly so that the magnetic spring null of the motor corresponds to the hydraulic valve null whenever the motor stator assembly is replaced.
The force motor of the present invention is a limited angle torque motor which is particularly suited for use in certain types of high pressure fluid proportional servo control systems including but not limited to aircraft controls to drive a proportional control valve of relatively short stroke. The fluid pressure may for example be on the order of 1,000 psi or more.
In such a motor, it would be desirable to provide for the quick, repeatable in-line replacement of the motor stator assembly. Also, it would be desirable to provide a simple and effective system or method for accurately setting the magnetic spring null of the motor with respect to the servo valve hydraulic null independent of the actual motor stator assembly, so that the motor stator assembly may be configured as an interchangeable plug-in module with interface electrical connector.